1. Field
The present disclosure relates generally to aircraft and, in particular, to composite structures in aircraft. Still more particularly, the present disclosure relates to reworking composite structures in an aircraft.
2. Background
Aircraft are being designed and manufactured with greater and greater percentages of composite materials. Some aircraft may have more than 50 percent of their primary structure made from composite materials. Composite materials may reduce the weight of an aircraft. With the decreased weight, improved payload capacities and fuel efficiencies may occur. Further, composite materials may provide longer life for various components in the aircraft.
Composite materials are tough, lightweight materials and may include fibers and resins. The fibers and resins may be combined to form a cured composite material.
With composite materials, inconsistencies may occur during manufacturing or use of an aircraft. These inconsistencies may require rework. For example, a composite structure in the form of a skin panel may require rework. If an undesired inconsistency is present in the skin panel, a portion of the composite material containing the inconsistency may be removed from an area of the skin panel. The removal of the composite material involves removing layers of composite material from the skin panel where the undesired inconsistency is located. The removal of the layers removes the inconsistency.
After the layers of composite material are removed, a patch may be placed into the area. The patch is then cured to rework the skin panel. The patch often is comprised of layers of composite material similar to the layers in the area in which the composite material was removed from the skin panel.
In curing the patch, heat and vacuum are often applied to the patch. Currently, heating of the patch may involve using a heat blanket. The heat blanket is placed over the patch. Additionally, pressure may be applied by placing a bag over the heat blanket and applying a vacuum to the bag.
Challenges are present with heating composite structures. Uniform heating of the patch is desirable in curing these types of structures. The uniform heating may provide for a desired curing in the patch resulting in a desired level of performance for the patch. Current heating systems using heat blankets may not provide as uniform of a level of heating as desired.
Therefore, it would be advantageous to have a method and apparatus that takes into account at least some of the issues discussed above, as well as possibly other issues.